Push-push switch with improved alternate make and break latching mechanism

ABSTRACT

A small switch suitable for remote control of a light or other low current electrical device, embodies a bridging contact thimble telescoped over and axially slidable on a guide stud disposed between spaced resilient contact blades which are engaged by the thimble upon projection of the thimble by a floating sleeve which has radial latch dogs alternately rotated by push operation into latching engagement with the ends of circumferentially spaced holding ribs in a surrounding housing, for latching the thimble in contact with the blades, and, on the next push operation, into position to be received between the ribs for spring-loaded retraction of the thimble and the floating sleeve by a coil spring enclosed within the thimble under compression between the guide stud and the remote end of the thimble.

United States Patent Congelliere et al.

[54] PUSH-PUSH SWITCH WITH IMPROVED ALTERNATE MAKE AND BREAK LATCHINGMECHANISM [72] Inventors: Peter Congelliere, 30636 Palos Verdes Drive,East, Inglewood, Calif. 90732; Horace Buttner, l50l Palos Verdes Drive,North, Harbor City, Calif.907l0 [22] Filed: Sept. 29, 1971 [21] Appl.No.: 184,884

52 US. Cl ..200/153 J, 200/64, 200/160 51 1111. C1. "H0111 3/52 [58]Field 61 Search ..200/64, 51.16, 153 J, 156,

Stevens.- ..200/166 CT X 14 1 Sept. 26, 1972 FOREIGN PATENTS ORAPPLICATIONS 222,708 8/1962 Austria ..200/160 1,362,299 7/1963 France..'.200/1 60 Primary Examiner-J. R. Scott AttorneyLynn H. Latta [5 7]ABSTRACT A small switch suitable for remote control of a light or otherlow current electrical device, embodies a bridging contact thimbletelescoped over and axially slidable on a guide stud disposed betweenspaced resilient contact blades which are engaged by the thimble uponprojection of the thimble by a floating sleeve which has radial latchdogs alternately rotated by push operation into latching engagement withthe ends of circumferentially spaced holding ribs in a surroundinghousing, for latching the thimble in contact with the blades, and, onthe next push operation, into position to be received between the ribsfor springloaded retraction of the thimble and the floating sleeve by acoil spring enclosed within the thimble under compression between theguide stud and the remote end of the thimble.

10 Claims, 10 Drawing Figures PUSH-PUSH SWITCH WITH IMPROVED ALTERNATEMAKE AND BREAK LATCIIING MECHANISM Background of the Invention FrenchPat. No. 1, 362,299 discloses a push button switch having a rotarylatching collar with camming teeth which are actuated by similar teethon the push button plunger.

Summary of the Invention v The invention is particularly characterized.by a compact assembly of coaxial, telescoping parts including apush-button plunger axially slidable but non-rotatable in a tubularcasing, an axially and rotatably floating sleeve within the plunger, anda metal thimble within the sleeve, adapted to be projected by a plungerstroke into bridging contact with a pair of contact blades, the sleevehaving circumferentially spaced radial latch dogs which are slidablebetween spaced axial housing ribs during the projection stroke, and arethen acted on with a rotary camming action by coacting lugs on the endof the plunger so as to be rotatably indexed into latching engagementwith the ends of the housing ribs for latching the thimble in engagementwith the contact blades. Upon a subsequent plunger stroke, the dogs areagain engaged by the plunger lugs and indexed into registry with axialslots alongside the housing ribs, into which they are received to allowthe thimble and sleeve to be retracted by their spring loading.

Description The general object of the invention is to provide apush-push switch of small dimension which is compact and of inexpensiveconstruction yet thoroughly reliable in operation and very durable, withminimum number of parts, totally enclosed, and with no exterior metalparts to rust or cause electrical shortage.

Other objects will become apparent in the following specifications andappended drawings, in which:

FIG. 1 is an axial sectional view of a switch embodying the invention,taken on line 1-1 of FIG. 2;

FIG. 2 is a cross-sectional view taken on line 2-2 of FIG. 1;

FIG. 3 is an axial sectional view showing the latching mechanism inelevation in an early stage of switch-closing operation;

FIG. 4 is a sectional view taken from the same viewpoint as FIG. 3 butwith the parts in a more advanced stage of closing operation and withsome parts broken away;

FIG. 5 is a cross-sectional view taken on line 5-5 of FIG. 3;

FIG. 6 is a detail sectional view taken on line 6-6 of FIG. 2;

FIG. 7 is a flattened view of the inner sides of portions of thelatching mechanism, shown in the latched position;

FIG. 8 is a flattened view of the same parts, shown approaching thelatching position;

FIG. 9 is a side view of the switch unit, and

FIG. 10 is an end view thereof.

Referring now to the drawing in detail, I have shown therein as anexample of one form in which the invention may be embodied, a switchsuitable for remote control of lights or other electrical devicesrequiring low current flow through the switch. In general, the switchcomprises a housing A, a push-button assembly B slidableaxially in atubular barrel portion of the housing, and electrical contacts C whichare cooperable to close and open a control circuit upon successivestrokes of plunger assembly B.

Housing A includes a cylindrical barrel portion 10 having externalthreads 11 for mounting it on a panel, light fixture or bracket 8 bysecuring means such as a pair of nuts 9, and an integral head portion12, which can be of rectangular block form in a plane normal to thebarrel axis, for housing a pair of spring contact blades 13 of thecontact assembly C. Barrel 10 (FIG. 1) has an axial succession of bore15, counterbore 16, chamber 17 of internally splined cross section, andan end counterbore 18, to receive respectively the stem 20 andcylindrical skirt 21 of plunger B, and a plurality of circumferentiallyspaced lugs 23 on the end of skirt 21. The lugs are axially slidablealongside two diametrically opposed axially extending pairs ofcircumferentially spaced, fixed ribs 24 (FIG. 5) in the counterbore 17,being thus retained against rotation while freely slidable for plungerprojection. At the forward end of plunger B (FIGS. 3 and 4) lugs 23 areprovided with spear-pointed camming teeth 25.

Telescoped into the cylindrical bore 126 of skirt 21 is a cylindricalsleeve 30 (Fig. 1) having on a forward end an annular head 26 providedwith a plurality of rearwardly projecting camming teeth 27 (FIG. 3) inaxially opposed relation to fixed cammingteeth 25 of barrel 10, andcooperable therewith to effect rotary indexing of sleeve 30 when thesleeve has been released for rotation by forward projection. Head 26further embodies a plurality of latch dogs 31 projecting radially fromalternate teeth 27, each dog 31 having a rear end of sawtooth forrndefining a camming ramp 32 extending diagonally the full width of thedog.

In retracted positions of sleeve 30, dogs 31 are received in ways 28defined along outer sides of the ribs of each pair of fixed ribs 24(FIG. 5). Ways 28 are deeper (of greater radius from the assembly axis)than axially extending spaces that are defined between the ribs 24 ofeach pair, such spaces being made more shallow by webs 29 between thesplines (FIG. 7). At the forward ends of ribs 24 and webs 29 arediagonal shoulders 49 defining camming ramps which extend from a pointof one rib of a pair to the near side of the other rib of the pair so asto define with said near side a latch keeper pocket 59. The outerdiameter of latch dogs 31 is greater than the inner diameter ofshoulders 49. Dogs 31 when urged rearwardly by spring-loaded retraction(hereinafter described) of plunger B, will engage shoulders 49 with acamming action such as to effect rotary indexing of sleeve 30 to movedogs 31 into latching pockets 59 to establish a latched-closed positionof the switch. Between the pairs of ribs 24 are flat lands 69 havingdiagonal forward ends defining camming ramps 79 which may assist theindexing to latched position by engagement with dogs 31 alternate tothose in latching position.

Housing head 12 has a rectangular open-front space 35 which is closed bya cover 36. Cover 36 has a space 37 communicating with space-35 todefine a contact chamber in which contact blades 13 are received andoperable. Head 12 has an integral transverse lug 38 projecting into capspace 37 and fitted therein for locating the cap cover and head inregistration at this one end of the assembly. At the other end of theassembly, housing 12 has a plurality of lugs 39 (laterally spaced so asto flank the contact blades 13) received in mating sockets in cap cover36, for registering the parts at that end of the assembly. Also at thatend of the assembly, contact blades 13 at their fixed ends are providedwith terminal tails 40 (FIGS. -1 and 6) which project through apertures41 in head 12 and are electrically connected tothe ends of conductors 42which are received in bores 43 in head 12. Tails 40 are spearpointed at44 (FIG. 6) and are driven through the insulation jackets of conductors42 to make penetrating, wedging contact with multiple wire cores thereofbefore attachment of cap cover 36. The ends of the wire cores aresolder-dipped at 45 (FIG. 1) to close them so that they will be securelyanchored by the penetrating tails 40, and can not pull out of the bores43. Cover 36 is secured to the housing by the interference fit of lugs38 and 39 in their sockets. Fusing of the lugs to the cover (e.g., bysolvent or heating) is preferably used for permanent attachment. Cover36 abuts the ends of blades 13 to secure the blades by clamping betweenthe cover and the housing.

Contact assembly C comprises the pair of blades 13, each having'a free,flexible end 50 of S-curve configuration terminating in a roundedcontact tip 51 (FIG. 3) projecting into head space 35, and a transitionportion 52, merging into the main body of the blade, normally spacedslightly from the opposed bottom area of cap space 37 so as to beyieldably retractable under pressure exerted by a coacting radialcontact flange 53 on the forward end of a cylindrical metal thimble 54carried by sleeve 30. The bottom face of cap space 37 has a contour,longitudinally of blades 13, such that the transition portions 52 of theblades will progressively bottom against the cap as they are flexedtoward the cap, and are thus supported against excessive bending atpoints remote from their contact tips 51. Wear life of the blades isthus greatly increased and early failure avoided.

Thimble 54 is loosely telescoped into the sleeve 30. At its forward endit is telescoped over a slidable on a guide stud 55 which is formed asan integral projection on cap'36. A coil spring 56 is received withinthe thimble 54 and is engaged under compression between its closed endand the shouldered end of stud 55, thus loading the thimble 54 andsleeve 30 for rearward retraction from the latched position. The rearend of plunger stem may be provided with a suitable button 60 (FIG. 9)for finger engagement to operate the switch. Operation In a normallyopen position of the switch (FIGS. 1 and 3) the plunger B and contactthimble 54 are retracted under the loading of spring 56, the contactflange 53 is separated from contact blade tips 51, the latter-areprojected to rearward limit positions of rest, and the latch dogs 31 arewithdrawn into the spaces 28 adjacent ribs 24 and are in axially-opposedregistration with plunger lugs 23.

In a first plunger stroke, in which finger pressure is applied to button60, the lugs 23 will advance into pres sure engagement with latch dogs31, the camming teeth 25, 27 reacting under the pressure to develop atorque thrust against sleeve 30. When the plunger nears the forward endof its stroke, the dogs 31 will clear the forward ends of ribs 24 andthe torque thrust will then rotate the sleeve 30 and its head 26 in thedirection indicated by the arrow in FIG. 7, until the dogs 31 areregistered with the ribs 24, as in FIG. 7. Their rear extremities willthen engage the camming shoulders 49 upon relaxation of pressure on theplunger and will be cammed into pockets 59, thus latching the sleeve 30in the forwardly projected position. In this position the contact flange53 of thimble 54 will be engaged with blade tips 51, pressing themforwardly so as to flex the blades 13 (FIG. 1) thus developing yieldingpressure between the contacts. The switch is thus latched in closedposition.

Upon a second plunger stroke, the teeth 25 will again engage the teeth27 with a camming action which will rotate the sleeve 30 on to aposition in which dogs 31 are again registered with the spaces 28adjacent ribs 24. Upon relaxing the pressure on plunger B, the sleeve30, thimble 54 and the plunger will be retracted by spring 56, the dogs31 sliding rearwardly into spaces 28 and the contact flange 53separating from blade tips 51. The switch is thus opened and will remainopen under the spring loading until the button 60 is again pushed.

I claim:

1. In a push-push switch, in combination:

a housing including a barrel and a transverse head at one end thereof;

a pair of resilient contact blades having movable free ends with contacttips in spaced relation on opposite sides of the barrel axis;

a cover secured to said head, said blades being secured between saidcover and said head;

a movable contact in axially opposed relation to said contact tips forbridging engagement therewith to close the switch;

means mounting said movable contact for axial movement to establish saidbridging engagement;

a plunger axially slidable in said barrel and engageable with saidmounting means when projected;

means yielding biasing said plunger for return to a retracted position;

latch means on said mounting means;

cooperating latch keeper means in said housing, en-

gageable with said latch, means to retain said mounting means inswitch-closing position;

said plunger having axial movement-transmitting means operable on afirst projecting stroke thereof to engage said mounting means and tomove it so as to effect engagement of said latch and keeper means forswitching closing;

said movement transmitting means being operable on a second plungerstroke to disengage said latch means from said keeper means so that saidmounting means may return to an open-switch position upon retraction ofsaid plunger.

2. A switch as defined in claim 1:

said movable contact comprising a thimble having forward end in axiallyopposed relation to said contact tips for bridging engagement therewith;

said mounting means comprising a sleeve in which said thimble ismounted;

said sleeve being rotatable and axially slidable in said barrel;

said latch means comprising radially protecting latch dogs on saidmounting means;

said barrel including internal circumferentially spaced axiallyextending guide ribs having said keeper means at their forward ends, andadjacent ways alongside said ribs, adapted upon rotational indexing ofsaid mounting means from its latching position, whereby to allowretraction of said thimble to a switch-opening position disengaged fromsaid contact tips;

said biasing means spring-loading said thimble and its mounting meanstoward said switch-opening position;

said plunger being slidable axially in said barrel and having a forwardend provided with radial lugs slidable in said ways, said keeper meansand dogs having opposed camming ramps cooperable to impart a rotationaltorque to said mounting means upon projection of said lugs against saiddogs in opposition to said spring loading, said plunger being operableupon one movement thereof to project said mounting means to a positionreleasing said dogs from said ribs and causing them to rotate topositions for latching engagement with said keeper means at the forwardends of the ribs upon release of said plunger for retraction, and upon asecond movement to engage said lugs against said dogs with a furthercamming action rotating said mounting means on to a position in whichsaid dogs are receivable in said ways, for spring-energized retractionof said thimble to said switch-opening position.

3. A switch as defined in claim 2, wherein said forward end of thethimble embodies a radial flange for bridging contact with said bladetips.

4. A switch as defined in claim 3, wherein said spring-loading meanscomprises a coil spring in said thimble engaged under compressionbetween said cover and housing.

5. A switch as defined in claim 4, including a guide stud carried by thecover and projecting into the forward end of said thimble, said coilspring being contained in said thimble, under compression between theend of said stud and the rear end of said thimble.

6. A switch as defined in claim 5, wherein said stud extends betweensaid contact blade tips.

7. A switch as defined in claim 1, wherein said free ends of the contactblades are of S-curvature including portions projecting into said casinghead from within said cap;

said cap having surfaces in opposed relation to said S-curvatureportions, said surfaces graduallydiverging from said blades at a lowangle such that said blades will progressively bottom against saidsurfaces with increasing deflection of said blades, so as to besupported against sharp bending.

8. A switch as defined in claim 1, wherein said housing includes a headportion integral with said barrel and having an open front, and a capclosing said open front, said stud being integral with said cap, saidcontact blades having fixed ends which are clamped between said cap andsaid head, said fixed ends having terminal tails bent at right anglesand projecting into slots in said head;

and a pair of conductors having ends extending into bores in said headand engaged by said tails with an anchoring and electrical connectionengagement, 9. A switch as defined in claim 8, wherein sald tails havespear points for penetration through insulation jackets of saidconductors, the latter embodying multiple-strand wire cores into whichsaid spear points penetrate and are wedged between the strands thereof.

10. A switch as defined in claim 9, wherein said wire cores havingprojecting ends which are solder-dipped to lock them together andthereby lock said conductors to said spear points.

1. In a push-push switch, in combination: a housing including a barreland a transverse head at one end thereof; a pair of resilient contactblades having movable free ends with contact tips in spaced relation onopposite sides of the barrel axis; a cover secured to said head, saidblades being secured between said cover and said head; a movable contactin axially opposed relation to said contact tips for bridging engagementtherewith to close the switch; means mounting said movable contact foraxial movement to establish said bridging engagement; a plunger axiallyslidable in said barrel and engageable with said mounting means whenprojected; means yielding biasing said plunger for return to a retractedposition; latch means on said mounting means; cooperating latch keepermeans in said housing, engageable with said latch means to retain saidmounting means in switchclosing position; said plunger having axialmovement-transmitting means operable on a first projecting strokethereof to engage said mounting means and to move it so as to effectengagement of said latch and keeper means for switching closing; saidmovement transmitting means being operable on a second plunger stroke todisengage said latch means from said keeper means so that said mountingmeans may return to an open-switch position upon retraction of saidplunger.
 2. A switch as defined in claim 1: said movable contactcomprising a thimble having a forward end in axially opposed relation tosaid contact tips for bridging engagement therewith; said mounting meanscomprising a sleeve in which said thimble is mounted; said sleeve beingrotatable and axially slidable in said barrel; said latch meanscomprising radially protecting latch dogs on said mounting means; saidbarrel including internal circumferentially spaced axially extendingguide ribs having said keeper means at their forward ends, and adjacentways alongside said ribs, adapted upon rotational indexing of saidmounting means from its latching position, whereby to allow retractionof said thimble to a switch-opening position disengaged from saidcontact tips; said biasing means spring-loading said thimble and itsmounting means toward said switch-opening position; said plunger beingslidable axially in said barrel and having a forward end provided withradial lugs slidable in said ways, said keeper means and dogs havingopposed camming ramps cooperable to impart a rotational torque to saidmounting means upon projection of said lugs against said dogs inopposition to said spring loading, said plunger being operable upon onemovement thereof to project said mounting means to a position releasingsaid dogs from said ribs and causing them to rotate to positions forlatching engagement with said keeper means at the forward ends of theribs upon release of said plunger for retraction, and upon a secondmovement to engage said lugs against said dogs with a further cammingaction rotating said mounting means on to a position in which said dogsare receivable in said ways, for spring-energized retraction of saidthimble to said switch-opening position.
 3. A switch as defined in claim2, wherein said forward end of the thimble embodies a radial flange forbridging contact with said blade tips.
 4. A switch as defined in claim3, wherein said spring-loading means comprises a coil Spring in saidthimble engaged under compression between said cover and housing.
 5. Aswitch as defined in claim 4, including a guide stud carried by thecover and projecting into the forward end of said thimble, said coilspring being contained in said thimble under compression between the endof said stud and the rear end of said thimble.
 6. A switch as defined inclaim 5, wherein said stud extends between said contact blade tips.
 7. Aswitch as defined in claim 1, wherein said free ends of the contactblades are of S-curvature including portions projecting into said casinghead from within said cap; said cap having surfaces in opposed relationto said S-curvature portions, said surfaces gradually diverging fromsaid blades at a low angle such that said blades will progressivelybottom against said surfaces with increasing deflection of said blades,so as to be supported against sharp bending.
 8. A switch as defined inclaim 1, wherein said housing includes a head portion integral with saidbarrel and having an open front, and a cap closing said open front, saidstud being integral with said cap, said contact blades having fixed endswhich are clamped between said cap and said head, said fixed ends havingterminal tails bent at right angles and projecting into slots in saidhead; and a pair of conductors having ends extending into bores in saidhead and engaged by said tails with an anchoring and electricalconnection engagement.
 9. A switch as defined in claim 8, wherein saidtails have spear points for penetration through insulation jackets ofsaid conductors, the latter embodying multiple-strand wire cores intowhich said spear points penetrate and are wedged between the strandsthereof.
 10. A switch as defined in claim 9, wherein said wire coreshaving projecting ends which are solder-dipped to lock them together andthereby lock said conductors to said spear points.